That's interesting as I found the Resolution Audio the opposite of what I think you mean by "hifi" (artificial/unnatural/unorganic?), but that's probably because I upgraded from a Benchmark DAC which is a bit artificial/clinical sounding.
As you say, the built-in pre is part of the plan because I still don't have a preamp and I'm not keen on getting too many boxes esp as I'm about to add a blueray player (BD-55) to my rack.
Btw, just got a set of Nordost Ti Pulsar Points - I'm still in shock as to how dramatic a difference they've made: more liquid, more open, more dynamic, more depth, more separation, tighter bass.